In an army selection process, the ratio of selected to unselected was 3:1. If 60 less had applied and 30 less selected, the ratio of selected to unselected would have been 5:1. How many candidates had applied for the process?
The mean of marks secured by 45 students in division A of class X is 69, 65 students of division B is 65 and that of 50 students of division C is 63. Find the mean of marks of the students of three divisions of Class X.